Compressor-controlling mechanism



F. D. HOLDSWO RTH.

COMPRESSOR CONTROLLING MECHANISM.

APPLICATION FILED DEC.I, 191s.

Patented Mar. 7, 1922.

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Specification of Letters Patent.

Patented Mar. 1, 1922.

Application iiled lbeeember 1, 1916. Serial n. 134,452.

To all whom it may concern: Be it known that I, FRED D; HoLnswoR'rH, a citizen of the United States, residing at Claremont, in the county of Sullivan and State of New Hampshire,have invented certain new and useful Improvements in Compressor-Controlling Mechanisms, of which the following is a full, clear,aiid exact specification.

My invention relates to compressor controlling mechanisms.

I has for its "object to control a compressor in an improved manner whereby the same may be automaticall unloaded or loaded as conditions vary. more specific object of my invention is to provide improved controlling mechanism especially adapted to multi-stage compressors wherein one set of inlet valves, as for instance those of the low pressure cylinder, are actuated to unload the compressor, and wherein another set of inlet valves, as for instance those of the high pressure cylinder, are subsequently actuated to complete the unloading of the compressor, theselast mentioned valves being controlled by improved means automatically responsive to the variations in pressure resulting from unloading the low pressure cylinder. These and other objects of my invention will, however, hereinafter more fully ap ear.

n the accompanying drawings, I have, for purposesof illustration, shown my inventlon as applied to atwo-stage compressor, although it will be readily understood that the same is not limited to a machine of the particular construction shown.

In these drawings,---

Fig. l is a partial sidev elevationof a compressor equipped; with my improvement,

certain portions of the same being broken.

away to facilitate illustration.

Fig. 2 is a central longitudinal sectional view through a portion of thecontrolling' vmechanism.

In this illustrative construction, have shown a compressor 1 mounted u on a suit able base 2 and having low and igh pressure cylinders 3 and 4 in which are movable pistons 5 and 6, the latter preferably, although not necessarily, being disposed in alignment and connected through a usual connection 7. Y e

As shown, the low pressure cylinder 3 repressed valves, the pressure I the usual cooling pipes ceiveszair from asuitable inlet 8 whose communlcation with the cylinder is controlled by a plurality of inlet or suction valves 9, only one of which isshoWm-while the aircomby the piston 5 passes out of this cylinder 3 through a plurality of discharge valves 10 of usual construction, only one of I which is shown. From these discharge fluid passes in the usual manner to an intercooler 11 equipped with 12 and connected to the high pressure cylinder 4. As in the usual construction, the supply of pressure fluid passes from this intercooler to the high pressure cylinder, through aplurality of inlet valves 13 of usual construction, only one of which is shown, and after the charge in the been compressed by the pi's-,

cylinder 4 has ton 6, the same is discharged from that cylinder through a plurality of discharge, valves 14 ofusual construction, only one-of which is shown, to a pipe 15 leading to a receiver 16. In the construction illustrated, the inlet valves 9 and 13 of the hi cylinders are each provi ed with depe stems 17 and are held normally in closed position by suitable means, as .by coiled springs 18. 'As' shown, a cylinder member 19 is disposed beneath each of these valves in such a manner that a combined *pis ton and plunger 20 movable in that cylinder,

nding their may engage with the lower end of the valve hand low pressure stem and thereby lift the valve from its seat to unload the cylinder. As shown, each of these cylinders 19 is also connected through suitable piping 21 with a cooperating' pipe 22 to which/the controlling mechanism is connected. I v

Thiscontrolling mechanism will first be described in connectionvwith the low pressure cylinder, and, inasmuch as the valves used in both cases are identical; with certain exceptions hereinafter noted, we will use the structure shown in- Fig. 2. In this figure, it will be noted that an unloader valve of standard construction, known in the art as a Judson valve, is connected'in the ipe 22 and is alsoconnected with a pipe 23 eading to apipe connection 24 connected to the receiver. Within this valve disposed a diaphragm 25-subject to receiverlpressure and having a plunger 26 dis osed above the same and normally depresse by a s ring 27 carried within asuitable adjusts. le casing 28 and exposed to the surrounding (in this case atmospheric) pressure through an opening 29. Beneath this diaphragm 25 is a plunger 30 which has lateral ports 31 therein communicating with a longitudinal passage 32, and is normally held in elevated position by a coiled spring 33. Beneath this plunger 30 is disposed a ported disk valve 34 controlling and communicating with ports 35 leading to the atmosphere, the disk 34; being normally held in elevated position by a lower coiled spring 36 and also being exposed to the pressure in the pipe 22 through a suitable aperture 37. Such a mechanism is well known in the art and its operation in connection with the compressor valves 9 is also well known. Briefly, however, it may be said that the valves 9 are lifted from their seats by the plungers 20 when the pressure in the receiver is suflicient to raise the diaphragm 25 and permit the plunger 30 to'rise and open communication between the receiver and the istons, while, when the receiver pressure alls below a predetermined limit, the pressure beneath the members 20 is exhausted through the ports 35 as a result of the dropping of the diaphragm and the consequent opening of the ports 35 by the downward movement of the plunger 30. Obviously, such an operation ofthe valves 9 of the low pressure cylinder will, therefore, occurv when the pressure in the receiver 16 drops below a predetermined amount.

In my improved construction, however, I have provided means whereby the high pressure cylinder may not be unloaded simultaneously with the low pressure cylinder, and wherein the unloading of the high pressure cylinder is brought about automatically and at the end of such an interval after the unloading of the low pressure cylinder as to give the desired results. This I accomplish by providing a connection between the controlling mechanism for the high pressure cylinder and a suitable space in which the pressure conditions vary automatically as a result of, and preferably subsequently to, the unloading of the low pressure cylinder.

In the form of my invention shown herein,

a connection 38 is provided between the intercooler and a bell-like casing 39 disposed over the unloading valve for the high pres sure cylinder above described in connection with the'low pressure cylinder. Thus,- instead of the diaphragm 25 of this controlling valve being open to atmospheric pressure on one side so that the valve will be operated relatively quickly upon a rise in receiver pressure, th1s diaphragm will not be actuated in sucha manner as to permit unloading of the high pressurecylinder until after the expiration of an interval, i. e. until the pressure in the intercooler has been caused to fall to a predetermined amount by the unloading of the low pressure cylinder.

In the use of my improved construction,

it will be noted that the action of the unloading mechanism is entirely automatic, the low pressure cylinder being unloaded when the receiver pressure exceeds a predetermined amount, While the high pressure cylinder is unloaded when the intercooler pressure, which has dropped as aresult of unloading the low pressure cylinder, has itself dropped to a predetermined amount, thereby inserting the desired time element between the unloading of the successive cyl' inders. Attention is also directed to the fact that by the use of my improvement, the controlling valve for the high pressure cylinder may be adjusted at the factory, and that no adjustment of the same on the part of the compressor tender is required. Thus, the

mechanism may function automatically to.

action and without the utilization of special mechanism, thus permitting my improvement to be applied at small expense. These. and other advantages of my improved construction will, however, be apparent to those skilled in the art.

While I have in this application specifically described one embodiment which my invention may assume in practice, it is to be understood that the form thereof shown herein is used for purposes of illustration only, and that the same may be modified and embodied in various other forms without departingfrom the spirit of the invention, it being my intention to include all such modifications within the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is z---- 1. In combination, a compressor having high and low pressure cylinders, means for unloading said low pressure cylinder, and

pressure cylinder, and automatically acting means operated by terminal pressure and responsive to varlatlons in pressure arising from the unloading of said low pressure cylinder for subsequently unloading said high pressure cylinder. 7

3. In combination, a compressor having high and low pressure cylinders, means for unloading said low pressure cylinder, automatically acting controlling means responsive to terminal pressure and variations in 5. In combination, a compressor having high and low pressure elements, means for unloading said low pressure element, and means actuated by terminal pressure and responsive to variations in pressure arising from the unloading of said low pressure element for subsequently unloading the other element.

6. In a compressor controlling mechanism, the combination comprising a compressor having high and lon pressure cylinders, an intercooler connected between the same, complete unloading systems for said high and low pressure cylinders, and means cooperating with the unloading system of said high pressure cylinder operative to control the same and responsiveto variations in pressure in said intercooler.

7. In a compressor controlling mechanism,

' the combination comprising a compressor having high and low pressure cylinders, a receiver, means for unloading said cylinders controlled by the pressure in said receiver, an intercooler connected to said cylinders, and means connected to said intercooler for delaying the unloading of said high pressure cylinder.

8. In a compressor controlling mechanism,

the combination comprising a compressor having high and low ressure elements, a receiver, means for unl oading one of said elements controlled by receiver pressure, an intercooler connected to said elements, and means connected to said receiver and responsive to pressure variations in said intercooler for controlling the unloading of the other element only.

9. In a compressor controlling mechanism,

the combination comprising a compressor having high and low pressure elements, a re ceiver, separate means'responsive to recelver pressure 'for unloading each of said elements,

an intercooler connected to said elements,

and means controlled by intercooler pressure controlling the connection of one of said unloading means to the receiver to unload the element controlled thereby.

10. In a compressor controlling mechanism, the combination comprising, a compressor having high and low pressure elements, a receiver, separate means for unloading said elements each actuated by receiver pressure, and means responsive to variations in pres sure arisingfrom the unloading of one of said elements for subsequently unloading the other. 1

11. In a compressor controlling mechanism, the combination comprising a coinpressor having high and low pressure elements, a receiver, separate means for unloading said elements each actuated by receiver pressure, an intercooler connected to said elements, and means connected to said intercooler for controlling the flow of receiver pressure through one of said unloading means only.

12. In a compressor controlling mechanism, the combination comprising a compressor having high and low pressure elements, a receiver, means including control ling valves for unloading each of said elements, said controlling valves being responsive to variations in receiver pressure, and means subjected to variations in pressure in the compressor spaces arising from-the unloading of one of said elements for delaying the response of one of said controlling valves to the action of receiver pressure thereon.

13. In a compressor controlling mechanism, the combination comprising a com-.

pressor having high and'low pressure elements, a receiver, means including controlling valve mechanisms for unloading each of said elements, said controlling valve mechanisms being responsive to variations in receiver pressure, and means for conducting variations in pressure in the mm pressor spaces arising from the unloading of one of said elements to the controlling valve mechanism controlling the unloading of the other of said elements for delaying response thereof to the action of receiver pressure.

14. In a compressor controlling mechanism, the combination comprising a compressor having high and low ressure cylinders, an intercooler connecte between the same, unloading mechanisms cooperating re-' spectively with said high and with said lowpressure cylinders and comprising members movable to load and unload said cylinders, means each independent of the other determining the movements of said members, and controlling means responsive to variations in pressure in said intercooler for controlling the one of said last mentioned means which cooperates 'with the high pressure cylinder.

15. In combination, a compressor having high and low pressure cylinders, a receiver, means including controlling valves for unloading said cylinders and: responsive to variat1ons in pressure in said receiver, an 1ntercooler connected to said .cylinders, and means for transmitting the variations in pressure in said intercooler to one ofsaid controlling valves to delay the operation thereofin the unloading of said high pressure cylinder.

16; In a compressor controlling mechanism, a compressor having high and low pressure cylinders, inlet valves for saidcylinders, a receiver, an int'ercooler between said cylinders, unloading mechanisms cooperating with said inlet valves and responslve to receiver pressure, and means for subjecting but oneof said unloading mechanisms to variations in pressure in said inter-' cooler for delaying the unloading of the cylinder controlled thereby.

17. In combination, a compressor having high and low pressure cylinders, means for unloading said low pressure cylinder, and automatically acting. means responsive to variations in pressure arising from the unloading of saidlow pressure cylinder and actuated by terminal pressure for subsequently completely unloading said high pressure 0 linder.

18. n combination, a compressor having high and low pressure cylinders, means for unloading said low pressure cylinder, and automatically acting means responsive to variations in pressure arising from the unloading of said low pressure cylinder and actuated by terminal pressure for subsequently unloading said high pressure cylinder during'a complete stroke.

19. In a compressorcontrolling mechanism, the combination comprising a compressor having high and low pressure elements,a receiver, means responsive to receiver pressure respectively operative to unload each of said elements, an intercooler connected to said elements, and separate means each solely controlling the connection between one of said unloading means and the receiver.

20. In a compressor controlling mechanism, the combination comprising a compressor having high and low pressure ele ments, a receiver, means responsive to receiver pressure and respectively operative to unload said elements; an intercooler connected. to said elements, and separate automatic means each controlling the connection between one of said unloading means and the receiver.

' 21.- In combination, a compressor having high and lowpressure cylinders, inlet valves for each of said cylinders, means for operating the .inlet valves of the low pressure cylinder to unload said cylinder, and autonausea 'matically acting means responsive to variahigh pressure cylinder to subsequently unload said high pressure cylinder.

23. In a compressor controlling mechanism, in combination, a compressor having high and low'pressure cylinders, a receiver connected to said cylinders,means including controlling valves normally unloading said cylinders upon a variation in pressure in said receiver. and an inter-cooler connected to said cylinders, one of said controlling valves being responsive to variations in pressure in said intercooler for delaying the operation of the controlling valve of said high pressure cylinder.

24. The combination with a multi-stage compressor, of means for unloading. the low pressure stage thereof, and means for unloading and re-loading a higher pressure stage governed as to bothits functions by the combined effects of the discharge pressure of that stage during normal loaded running and the pressure in said compressor at a point between the suction side of that stage and the intake of said compressor.

25. The combination with. a multi-stage compressor, of means for unloading the low pressure cylinder thereof, and means for unloading a higher stage cylinder thereof including an element continuously subjected to the combined effects of compressor discharge pressure and the pressure in said compressor at a point between the suction side of said last mentioned stage and the intake of said compressor.

26. In combination with a compressor cylinder having automatically acting inlet valves, an unloading mechanism, and means for controlling said unloading mechanism comprising a pressure fluid inlet to said mechanism, means for controlling a flow of pressure fluid through said inlet having means for governing the movements thereof including a member normally biased in one direction and movable in the opposite direction by fluid under pressure, and means for controlling said governing means.

27. In combination With a compressor having automatically acting inlet valves, an unloading mechanism, means for controlling said unloading mechanism comprising a pressure fluid inlet to said mechanism, means for controlling a flow of fluid through said inlet to unload said compressor and from said mechanism to load the compressor, and means for controlling .said flow controlling means.

28.111 combination with a compressor having automatically acting inlet valves, an unloading mechanism, means for controlling said unloading mechanism comprising a pressure fluid inlet to said mechanism. valve means for controlling a flow of pressure fluid through said inlet, and pressure fluid actuated means for controlling said flow controlling means including a valve controlling member whose position is governed by spring pressure and by the diflerence between compressor discharge pressure and the pressure at a point in said compressor 'llQI'O the pressure varies when the compressor is loaded and unloaded.

ii). In combination with a compressor having automatically acting inlet valves, an unloading mechanism, means for controlling said unloading mechanism comprising a pressure fluid inlet to said mechanism, means comprising a valve for controlling a flouof fluid throughsaid inlet to unload said compressor and from said mechanism to load the compressor, and fluid actuated means comprising a member engagable with said valve for controlling the latter, said member being subjected to different pres sures when said compressor is loaded and when it is unloaded.

30. In combination, a compressor having a plurality of compression chambers, unloading mechanism for each of said chambers, and means for effecting sequential operation of said unloading mechanisms comprising control means for each of said mechanisms each controllable by the same medium the other and means governed by the effects produced in said compressor by the operation of one of said control means for controlling the operation of the other.

31. In a compressor controlling mechanism, a valve controlling piston, means for controlling the movements of the latter including a valve, :1, fluid pressure controlled actuating element. a spring engaging said element, said spring forcing said element in a direction to close said valve, a connection between a space in communication with the compressor discharge and a space at the lower side of said element surrounding said valve, and a connection between the space at the upper side of said element and a space in the compressor wherein a reduction in pressure from that, during loaded running occurs on unloading of said conipressor.

In testimony whereof I affix my signature.

FRED D. HOLDSIVORTI-I. 

